Lethal bird flu is now spreading in Australia. This is bad news for many native species.
New federal government analysis suggests close to one in five Australian bird and mammal species is at high, very high or extreme risk. But this risk assessment omits something vital – how genetically well-equipped the species is to fight the virus.
While species such as black swans are likely to be very hard-hit, others such as wild ducks are expected to be less affected. One reason for this is different immune systems – some are more or less able to fight the virus. But there’s a more significant factor – how much variation there is in key immune system genes across populations.
Right now, we don’t have an overview of which threatened species are at highest risk based on this. If we urgently create a national immune-risk map for species at risk, we can act to protect those in most danger.
Black swans are likely to be hard hit by bird flu, unlike wild duck species. The difference lies in their immune systems.irmaferreira/Getty
Why immune gene variations matter
When a virus enters an animal’s body, its immune system must first detect it, then respond. Key immune genes help determine if an animal fights off infection, becomes seriously ill or dies.
Different individuals will have slightly different immune responses based on variations at different immune genes. Some variants will allow an individual to survive the virus, and others won’t. This is why diversity in these genes is critical across the species.
Large wildlife populations often have a wide array of variants at each immune gene. This acts as biological insurance – when a new disease arrives, some individuals will be more able to survive. But if a species becomes threatened and its population falls, it’s likely to lose much of this protective diversity.
If the remaining individuals share similar vulnerabilities, a lethal disease such as H5N1 bird flu could be enough to push the species closer to extinction.
Threatened species are often immunologically fragile
Australia’s wildlife faces threats such as habitat loss, climate change, invasive species, pollution and disease. These threats not only reduce population size – they erode genetic diversity.
Small, fragmented populations may have enough genetic diversity to look viable in the short term. But when a new disease arrives, they may lack the breadth of variation at the immune genes needed to survive the new disease. This is a large, hidden vulnerability.
The orange-bellied parrot is a species that worries us deeply. The small, migratory parrot is one of Australia’s most endangered birds. Just 86 birds are left in the wild, with a few hundred more in captive breeding populations.
Our previous research found the parrot has suffered a dramatic loss of genome-wide diversity over the past century – including variation in immune genes.
If H5N1 infects these parrots, they may lack the immune gene variants needed to buffer the species against severe disease.
Many orange-bellied parrots are being reared in captive breeding programs.Outback to Coast/Getty
Tasmanian devils are similarly at risk. These iconic marsupials have critically low immune gene diversity due to population bottlenecks over the past 5,000 years. This left them vulnerable to the contagious devil facial tumour disease, which saw populations plummet with local declines of 95%, and an estimated 80% decline across Tasmania since the disease arose in the 1990s. Our preprint research shows facial tumour disease is still eroding immune gene diversity.
These scavengers are likely to be exposed to bird flu by eating carcasses, and we know which devil populations eat seabirds. The question will be whether devils have enough immune variation to respond to H5N1.
How a national immune-risk map could help
While we know how some species are likely to respond to the virus, the picture is far from complete.
We could fill in the blanks quickly, using DNA samples held in museums or from animals in zoos to generate genomic data on many more species.
We could then analyse immune gene variation across different populations of each species to measure how diverse they are. This approach could reveal populations that have lost important immune variants and may be particularly vulnerable to bird flu.
The Threatened Species Initiative, has collected this data for more than 125 threatened species. But there are hundreds more threatened animal species for which we have no data and no samples.
If we worked quickly to create a national immune-risk map, wildlife managers could focus surveillance, vaccination and protection efforts on the populations likely to be at most risk.
Importantly, they could establish new captive populations before the virus arrives, using breeding programs to maximise immune fitness and keep inbreeding to a minimum.
This is not science fiction. We led immune-guided conservation work in Tasmanian devils, where data on immune genes shape decisions around breeding. The end result: devil joeys with stronger immune systems.
If we use this approach for more at-risk species, we could better protect wildlife from bird flu and future diseases.
No time to waste
Responses to wildlife diseases are often reactive. Animals start dying in large numbers and then we investigate. This approach will be much too slow to respond to the fast-moving H5N1 strain.
Australia has world-leading wildlife genomics expertise, valuable museum and zoo collections, threatened species recovery programs and growing genome resources.
What’s missing is a coordinated way to translate immune gene data into practical action.
It’s not too late. But we have to act fast to identify species and populations with low immune diversity and roll out measures before irreversible losses occur.
Katherine Belov receives funding from the Australian Research Council, including through the ARC Centre for Excellence in Peptide and Protein Science.
Carolyn Hogg receives funding from the Australian Research Council including through the ARC Centre of Excellence for Advanced Peptide & Protein Engineering, the NSW government and the Australian Government. She is affiliated with the Biodiversity Council.
Australia has confirmed deadly H5N1 bird flu has been found in 102 wild seabirds across five states at the time of writing, including the country’s first mass death of birds.
The question is no longer if this virus can harm Australian wildlife, but whether we should use every available tool to protect species most at risk.
Vaccination cannot stop H5N1 spreading through wildlife. But it could prevent an outbreak from killing all of the at-risk species in an area – a tragic local extinction.
Australia should begin targeted vaccination of threatened birds. It should also urgently develop a strategy for seals and sea lions, rather than waiting until thousands are dead.
A policy exists, but action remains too cautious
Australia has a national policy that allows emergency vaccination of rare, protected and valuable birds, including animals in zoos, sanctuaries, breeding programs and some managed wild populations.
The government has also purchased an inactivated H5 vaccine – containing no live virus – and is running pilot studies in captive non-poultry birds.
This is important groundwork, but not yet a public program comparable with New Zealand’s ambitious and proactive approach to vaccinate five of the country’s rarest birds before the arrival of H5N1.
Australian zoos and sanctuaries have received funding to strengthen biosecurity and captive “insurance populations”. Pilot vaccinations are underway, but the government has not announced which threatened species will receive wider vaccination, where, or when.
More importantly, the policy excludes non-avian (bird) species, meaning marine mammals are not considered despite their known vulnerability to H5N1. No plans have been announced to the public for Australian vaccination trials for seals or sea lions.
What overseas programs show
New Zealand prepared before H5N1 arrived. After species-specific trials, it began vaccinating about 300 core breeding birds of rare species, including k?k?p?, takah? and black stilts. These are captive or closely managed populations whose individuals can be found, vaccinated twice and monitored.
The United States acted after H5N1 killed 21 critically endangered California condors. By October 2024, 207 captive and free-flying condors had been vaccinated. The vaccine was judged safe, although two birds had treatable adverse reactions.
France has conducted a vaccine trial in wild king penguin chicks on the French sub-Antarctic island of Crozet. The vaccine produced strong, virus-neutralising antibodies without detected adverse effects.
These programs do not prove vaccination will prevent every infection. But it could lessen severe disease and reduce the number of animals that die in threatened populations.
The marine mammals most at risk are the sea lion, fur seal and elephant seal, while the Tasmanian devil and eastern quoll (pictured) are the highest-risk species on land.Rexness/flickr, CC BY
Which species should Australia vaccinate?
Broadscale vaccination of free-ranging wildlife is unrealistic. Most H5 vaccines require two doses, and most wildlife is difficult to capture once, let alone being recaptured for a booster and blood test.
The best candidates are small populations of at-risk species that are either easily accessible or already under management. For example, threatened birds in zoos or breeding centres, or small, known colonies with tracking or regular handling.
On Tuesday, the Australian government released a list of at-risk species, that showed almost one-in-five Australian bird and mammal species is at high, very high or extreme risk from the virus.
Five bird species are at extreme risk – the Christmas Island frigate bird, Houtman albatross, Herald petrel, imperial shag on Heard Island and imperial shag on Macquarie Island. The marine mammals most at risk are the sea lion, fur seal and elephant seal, while the Tasmanian devil and eastern quoll are the highest risk species on land.
Decisions must balance extinction risk, exposure to the virus, cost, vaccine performance, whether enough animals can be reached, and whether capture would cause unacceptable stress. Vaccination must sit alongside existing biosecurity, surveillance and conservation measures – not replace them.
Australia needs a seal plan
H5N1 has decimated seal and sea lion populations across South America and the Southern Ocean. More than 17,000 southern elephant seal pups were killed in Argentina in 2023. An estimated 13,359 pups died at the Australian sub-Antarctic Heard Island in 2025, believed to be from the virus. Southern elephant seals were listed as vulnerable on the IUCN Red List in April, in part because of the catastrophic mortality caused by bird flu. It will take decades for these populations to recover.
Australia’s most vulnerable seals include the endangered Australian sea lion, Australian and long-nosed fur seals, and southern elephant seals. H5N1-positive terns have already been found at Seal Bay on Kangaroo Island, home to a major Australian sea lion breeding colony. Southern elephant seals have a large breeding colony on Australia’s sub-Antarctic Macquarie Island, which remains free of H5N1 at this time.
There is currently no bird flu vaccine designed specifically for marine mammals. A United States trial aimed at protecting endangered Hawaiian monk seals found a vaccine developed for cattle was safe in northern elephant seals and produced measurable antibodies.
This was the closest comparable species for which a safe, conditionally licensed vaccine was available. Developing and approving a separate vaccine for every wildlife species is costly and time-consuming, so conservation programs commonly adapt vaccines already approved for domestic animals.
Now is the time to act
Australia should identify priority seal colonies now, trial candidate vaccines in a suitable surrogate species and plan how vaccination could be deployed. We should not wait to learn how susceptible these animals are by watching more mass deaths unfold.
Vaccination is not a silver bullet. But when a disease can erase years of conservation work in weeks, we should not wait for perfect certainty. It’s time to act before catastrophe.
Jane Younger receives funding from the Australian Research Council, National Geographic Society, Rolex, WIRES, the Marine Megafauna Research Fund and Lindblad-National Geographic. She is affiliated with the University of Tasmania.
The NHS has been told it must become more resilient to increasingly frequent heatwaves supercharged by the climate crisis, as the UK government puts adaptation to extreme heat high on its agenda. But what other public services are already feeling the strain?
The impacts of a changing climate – from unprecedented rainfall and landslides to heatwaves fuelled by warming seas – are increasingly being felt across New Zealand.
But that doesn’t mean they’re being shared equally.
One tetraplegic man, evacuated from his home, reportedly spent the night in a police station after no hospital or rest home could accommodate him.
More recently, amid flooding in Oamaru last month, one woman trying to evacuate her blind nephew and another who uses a wheelchair found floodwaters made it impossible to push the wheelchair to her vehicle, leaving them stranded.
Extreme weather events like these are just one part of the picture. In my recently published research, those I interviewed described a wide range of climate-related concerns.
But there was a common message: disabled people want not only to be heard, but to play a leading role in guiding how New Zealand adapts to a changing climate.
Yet disabled people are still too often overlooked in climate policy and adaptation planning. Of 123 central government climate policy documents we analysed, only 29 mentioned disability at all and just seven discussed it in any substantive way.
The pattern is reflected internationally. One global study of more than 1,600 articles on adaptation initiatives found only 1% explicitly considered disabled people.
Even before climate change is considered, many disabled people in Aotearoa face barriers that affect their health, wellbeing and financial security.
They are less likely to be in paid employment, more likely to live in substandard rental housing, and more likely to experience material hardship and poverty. These existing inequities leave many with fewer resources to prepare for, respond to and recover from climate-related impacts.
These impacts are often compounded for disabled people who experience other forms of marginalisation, including M?ori, Pacific, migrant and refugee communities. As one study participant put it: “the deck is stacked against people”.
When discussing climate risks, those I interviewed raised issues from extreme heat to food security. Still, the ongoing impact of extreme weather events proved the greatest and most immediate concern.
Participants identified barriers across emergency preparedness, response and recovery.
This included information that was not available in accessible formats, a lack of inclusive disaster risk reduction programmes, inaccessible temporary accommodation and financial barriers to preparing for emergencies.
Many also described difficulties accessing safe and timely evacuation, with evacuation centres and emergency services often proving inaccessible. They wanted emergency information to include practical details, such as whether evacuation centres could accommodate disabled people.
Power outages created other challenges. Many disabled people rely on electricity not only for medical equipment, but also to charge mobility aids such as powered wheelchairs.
Experiences like these left many feeling that disabled people are not prioritised in emergency planning or response efforts, ultimately eroding trust in the system.
The value of lived experience
It would be a mistake, however, to view disabled people only as those at greater risk.
Those I spoke with repeatedly emphasised that their lived experience gives them valuable expertise in adapting to change. After all, disabled people and their wh?nau are already well versed in adapting to an inaccessible world.
As one participant observed, living with disability often means “thinking about things nobody wants to happen”. That experience gives disabled people valuable expertise in anticipating risk and adapting to disruption.
Elsewhere, the Disabled Person’s Assembly has worked with Civil Defence and emergency services in Christchurch and Dunedin to improve disability-informed preparedness.
The Wellington Region Emergency Management Office has produced an emergency preparedness guide developed by and for disabled people.
As climate impacts become more frequent and severe, the disabled community must be at the forefront of work to adapt, as key stakeholders and agents for change.
The work to build a more accessible, climate-adapted future is necessary to build a more adaptive, creative and diverse future where no one is left behind.
Raven Cretney received funding for this research from the National Science Challenge Resilience to Nature’s Challenges Kia manawaroa – Ng? ?kina o Te Ao T?roa. She currently receives funding from the Ministry of Business, Innovation and Employment's Endeavour Fund and is a member of the Disabled Persons Assembly New Zealand.
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